SAN DIEGO _ Police were searching downtown San Diego and East Village looking for a man on a bicycle who used a hammer to strike an apparent transient on the head Wednesday.
Paramedics took the victim to a trauma center, but no information on the extent of his injuries was immediately available.
A passer-by called 911 about 6:20 a.m. local time, San Diego police said, and investigating officers determined that the man had been attacked about two blocks away.
The attacker was riding a royal blue mountain bike and wore a backpack, police said.
Officers were questioning possible witnesses and looking for surveillance camera video that could help them trace the cyclist's path.
Police said there have been a number of attacks on the homeless in the last few weeks in which sleeping men were stuck on the head. The victim in the Wednesday assault was awake, and a witness saw him arguing with a man shortly before the attack was reported.
In what is believed to be a separate violent outbreak, four homeless men were attacked last week and three of them died from severe upper body wounds. Two were set on fire after being attacked. Homicide investigators arrested a suspect on Thursday, but he was released from jail on Monday when authorities said they didn't have enough evidence against him to press charges.
